2020-11-23 18:02:41

by Jani Nikula

Subject: [PATCH 2/9] relay: require non-NULL callbacks in relay_open()

There are no clients passing NULL callbacks, which makes sense as it
wouldn't even create a file. Require non-NULL callbacks, and throw away
the handling for NULL callbacks.

Suggested-by: Christoph Hellwig <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Signed-off-by: Jani Nikula <[email protected]>
---
kernel/relay.c | 14 ++------------
1 file changed, 2 insertions(+), 12 deletions(-)

diff --git a/kernel/relay.c b/kernel/relay.c
index b51343642bf4..d9b8185161a8 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -291,13 +291,6 @@ static int remove_buf_file_default_callback(struct dentry *dentry)
return -EINVAL;
}

-/* relay channel default callbacks */
-static struct rchan_callbacks default_channel_callbacks = {
- .subbuf_start = subbuf_start_default_callback,
- .create_buf_file = create_buf_file_default_callback,
- .remove_buf_file = remove_buf_file_default_callback,
-};
-
/**
* wakeup_readers - wake up readers waiting on a channel
* @work: contains the channel buffer
@@ -472,11 +465,6 @@ static void relay_close_buf(struct rchan_buf *buf)
static void setup_callbacks(struct rchan *chan,
struct rchan_callbacks *cb)
{
- if (!cb) {
- chan->cb = &default_channel_callbacks;
- return;
- }
-
if (!cb->subbuf_start)
cb->subbuf_start = subbuf_start_default_callback;
if (!cb->create_buf_file)
@@ -542,6 +530,8 @@ struct rchan *relay_open(const char *base_filename,
return NULL;
if (subbuf_size > UINT_MAX / n_subbufs)
return NULL;
+ if (!cb)
+ return NULL;

chan = kzalloc(sizeof(struct rchan), GFP_KERNEL);
if (!chan)
--
2.20.1

2020-11-25 02:01:08

by Christoph Hellwig

Subject: Re: [PATCH 2/9] relay: require non-NULL callbacks in relay_open()

On Mon, Nov 23, 2020 at 07:59:22PM +0200, Jani Nikula wrote:
> There are no clients passing NULL callbacks, which makes sense as it
> wouldn't even create a file. Require non-NULL callbacks, and throw away
> the handling for NULL callbacks.

Looks good,

Reviewed-by: Christoph Hellwig <[email protected]>